Ground waves
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Transcript of Ground waves
RADIO-FREQUENCY
WAVE PROPAGATION
BY:
Rea Jhoy Lastimosa
Christian Joseph Garniel
There are three basic paths that a radio signal can take
through space
• Ground waves
• Sky waves
• Space waves
GROUND WAVES
(SURFACE WAVES)
Ground Waves
(Surface waves)
• Leaves the antenna and remains close to the earth.
• follow the curvature of the earth
• strongest at the low and medium frequency
ranges.
• 30KHz – 3MHz range
• can propagate for hundreds and sometimes
thousand of miles at these low frequencies.
Effects of the Ground
surface wave is very dependant upon the nature of the
ground of which the signal travels. Such as the ff:
• Ground conductivity
• Terrain roughness
• Dielectric constant
Effects of the ground
• at lower frequency ground penetration is
greater
• at higher frequency ground penetration is
smaller
Ground Conductivity depends on the ff.
• Soil type and the moisture content ---rich
agricultural or marshy land
• Salty sea water
• Dry sandy terrain and city centers
Classification Band Frequency Range Characteristic
Extremely low 30 - 300 Hz Ground waves
Voice Frequency 300 Hz – 3 KHz Ground waves
Very low Frequency 1.5 – 20 KHz Ground waves
Low Frequency 30 – 300 KHz Ground waves
Meduim Frequency 300 – 3000 KHz Ground/ sky waves
High Frequency 3 – 30 MHz Sky waves
Very high Frquenncy 30 – 300 MHz Space waves
Ultra high Frequency 300 – 3000 MHz Space waves
Superhigh Frequency 3 – 30 GHz Space waves
Extremely High Frequency 30 - 300GHz Space waves
Infrared > 300 GHz Space waves
THANK YOU!!!
GOD BLESS